Faulkner isn't as print "readerly" as some writers--he is better when his work is read aloud, when it is heard by a listener who is breathing at the same rate as the reader. When I was in graduate school I had the opportunity one semester to read both Faulkner and Henry David Thoreau, and they are polar opposites as writers. Thoreau addressed the page much differently, I daresay he did a lot of proof reading and revisions, and his text is meant to be seen by the reader--if you listen to a recorded version of Walden you miss a lot. I found I had to go back to the book to see what he was talking about (sketches and figures and such). I can't tell you the history of how Faulkner wrote, but I surmise that editing did happen at some point in time because "corrected" versions of his work kept appearing.

SRS